[OJB-developers] extent problem,proxies

[Georg S. <ge...@me...>]

Hi,

I ran into an interesting problem. It goes like this:

I have a class A which implements an interface IA. repository.xml
therefore has an extent section. A is loaded with a dynamic proxy.

I can now do OQL queries like the following without a problem:

select anyIA from IA where .....

The problem starts when I say:

select anyA from A where ....

I don't get any results back due to the following:

In RsIterator, getIdentityFromResultSet() the following happens,

return new Identity(getExtentClass(),pkValues);

getExtentClass() in the end calls the DescriptorRepository
getExtentClass() method and assigns the first available baseclass or
interface(another problem I'll come to in a minute)
in our case this is IA

in PersistenceBrokerImpl , public ManageableCollection
getCollectionByQuery(Class collectionClass, Query query, boolean lazy)

the following lines are reached

if (itemClass.isAssignableFrom(candidateClass))
{
 tmpMap.add(candidate);
}

itemClass would be A in our case and candidateClass is IA and since it is
obviously not possible to cast IA onto A, the object is not added to the
result.


Another possible problem in this respect could be the fact mentioned
earlier that  the method getExtentClass(Class clazz) in
DescriptorRepository just returns the first baseclass or interface it
encounters, so if a class is a member of various extents a random
baseclass or interface will be returned as first one in each run of a
program due to the fact that

        Iterator iter = m_DescriptorTable.values().iterator();

ist called and since m_DescriptorTable is a Hashtable it doesn't guarantee
any special order of values returned.

Regards

Georg